21390330168 has 96 divisors (see below), whose sum is σ = 59969473200. Its totient is φ = 6879688704.

The previous prime is 21390330161. The next prime is 21390330173. The reversal of 21390330168 is 86103309312.

It is a super-3 number, since 3×21390330168³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21390330161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4743771 + ... + 4748277.

Almost surely, 2^21390330168 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21390330168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29984736600).

21390330168 is an abundant number, since it is smaller than the sum of its proper divisors (38579143032).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21390330168 is a wasteful number, since it uses less digits than its factorization.

21390330168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6821 (or 6814 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The spelling of 21390330168 in words is "twenty-one billion, three hundred ninety million, three hundred thirty thousand, one hundred sixty-eight".